//判断是否为闰年
function judge() {
    let year = parseInt;
    year = prompt('请输入年份：', 0);
    if ((year % 4 === 0 && year % 100 !== 0) || year % 400 === 0) {
        document.write(`${year}是闰年`);
    } else {
        document.write(`${year}不是闰年`);
    }
}
judge();